Dental restorations or prostheses are often manufactured using automated processes. In such automated processes ceramic and/or glass-ceramic materials are often used which also allow for making high-quality dental restorations because of their good physical, aesthetic and biological properties. Typically the manufacturing process for such restorations includes the steps of capturing data representing the shape of a patient's teeth, designing at least part of the dental restoration based on the captured data using computer-aided design (CAD) software, and manufacturing the dental restoration on an automated Computer Numerical Controlled (CNC) machine. An exemplary CNC machine for making dental restorations is available from 3M ESPE AG (Seefeld, Germany) under the trade designation LAVA™ Form Milling Unit.
Machines of this type are designed to automatically machine a dental restoration or parts of a dental restoration. To permit continuous use, some of these machines are equipped with an input magazine holding multiple blank workpieces that are automatically fed into the machine for sequentially producing multiple dental restorations without the need of intervention. Accordingly such machines typically also have an output magazine that receives finished dental restorations or precursors of a dental restoration.
In particular for machines that produce dental restorations by removing material from a blank, for example by milling or grinding, it is desirable that the removed material can be discharged from the machine, for example to avoid interruptions in manufacturing to dispose of accumulated material. It is further desirable to avoid wear on machine parts due to material particles or dust penetrating between cooperating components. It is also beneficial to avoid cross-contamination of dental restorations or precursors with material particles from previous workpieces, especially if they are made of different materials.
Although the current machines may provide a variety of advantages, there is still a need for a process and device which allows reliable manufacturing of dental restorations relatively inexpensively, and at a high quality level.